In recent years, single-atom catalysts (SACs) with separated active centers and high atom utilization have grown significantly as a significant area of catalytic research. In catalytic applications, SACs of various kinds have demonstrated exceptional performance, so the study of the catalytic mechanism of SACs provides a clearer direction for the preparation of catalysts with high performance. Strong linkages between the single atoms and the support are necessary to overcome the tendency of single atoms to aggregate into clusters, which is called metal-support interaction (MSI).
View Article and Find Full Text PDFNi supported on N-doped carbon is rarely studied in traditional catalytic reactions. To fill this gap, we compared the structure of 1 and 6 wt% Ni species on porous N-free and N-doped carbon and their efficiency in hydrogen generation from gaseous formic acid. On the N-free carbon support, Ni formed nanoparticles with a mean size of 3.
View Article and Find Full Text PDFSingle-atom catalysts with ionic Pd active sites supported on nitrogen-doped carbon nanotubes have been synthesized with a palladium content of 0.2-0.5 wt %.
View Article and Find Full Text PDFFormic acid is a widely used commodity chemical. It can be used as a safe, easily handled, and transported source of hydrogen or carbon monoxide for different reactions, including those producing fuels. The review includes historical aspects of formic acid production.
View Article and Find Full Text PDFFormic acid derived from biomass is known to be used for hydrogen production over Pd catalysts. The effects of preparation variables, structure of the carbon support, surface functional composition on the state of Pd, and catalytic properties of the samples in the vapor-phase decomposition of formic acid were studied. In all catalysts derived from Pd acetate, metal particles visible by conventional TEM had similar sizes, but the adsorption capacity towards CO responded strongly to N-doping of the carbon surface.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2015
Amorphous, low-porosity carbon spheres on the order of a few micrometers in size were prepared by carbonization of squalane (C30H62) in supercritical CO2 at 823 K. The spheres were characterized and used as catalysts' supports for Pd. Near-edge X-ray absorption fine structure studies of the spheres revealed sp(2) and sp(3) hybridized carbon.
View Article and Find Full Text PDFChem Commun (Camb)
May 2012
The rate of hydrogen production from vapour-phase formic acid decomposition can be increased by 1-2 orders of magnitude by doping a Pd/C catalyst with potassium ions. Surface potassium formate and/or bicarbonate species could be involved in the rate-determining step of this reaction.
View Article and Find Full Text PDFTransient response and temperature-programmed desorption/reaction (TPD/TPR) methods were used to study the formation of adsorbed NO(x) from N2O and its effect during N2O decomposition to O2 and N2 over FeZSM-5 catalysts at temperatures below 653 K. The reaction proceeds via the atomic oxygen (O)(Fe) loading from N2O on extraframework active Fe(II) sites followed by its recombination/desorption as the rate-limiting step. The slow formation of surface NO(x,ads) species was observed from N2O catalyzing the N2O decomposition.
View Article and Find Full Text PDFInteraction of N2O at low temperatures (473-603 K) with Fe-ZSM-5 zeolites (Fe, 0.01-2.1 wt %) activated by steaming and/or thermal treatment in He at 1323 K was studied by the transient response method and temperature-programmed desorption (TPD).
View Article and Find Full Text PDF